Area Code 503 History:
Area code 503 was put into service. In 1995 area code 503 was split to form area code 541. In 2000 area code 503 was partially overlaid with area code 971 and in 2008 the overlay was extended to all of area code 503.
Counties in Oregon within area code 503 include:
Clackamas County, Clatsop County, Columbia County, Linn County, Marion County, Multnomah County, Polk County, Tillamook County, Washington County, and Yamhill County.
Major cities or places in Oregon within area code 503 include:
Area codes 503 and 971 serve northwest Oregon including the larger cities and communities of Aloha, Beaverton, Gresham, Hillsboro, Keizer, Lake Oswego, Mcminnville, Milwaukie, Oregon City, Portland, Salem, Tigard, Tualatin, West Linn, Woodburn in addition to many smaller communities.